Liquid-fuel-burning apparatus



Aug. 31, 1926.

A. H. BALLARD LIQUID FUEL BURNING APPARATUS Filed Dec. l2. 1923 WMM Patented Aug. 3l, 1926..

UNITED STATES YPATENT OFFICE ARTHUR H. BALLARD, OF BOSTON, MASSACHUSETTS, ASSIG-NOR TO BALLARD OIL BURNING'EQUIPMENT COMPANY, OF BOSTON,

OF MASSACHUSETTS.

MASSACHUSETTS, A CORPORATION LIQUID-FUEL-BURNING APPATS. i

Application led December 12, 1923. Serial No. 680,158.

This inventionrelates to oil burning apparatus and more particularly to controllin devices for automatically regulating the fue supply. v

The invention will-be best understood by reference to the following description when taken in connection with theaccompanying illusti ation showing one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings,-

Fig; 1 is a front elevation of an apparatusembodying one form of the invention;

Fig. 2 is a sectional elevation o n theline 2 2 in Fi 1 showing the air pressureycontrol for the oil supply valve;

Fig. 3 isa central sectional eleva-tion on an enlarged scale showing the burner; and

Fig. l1-is`a side elevation of the burner and its connections.

Referring to the drawingsand to the embodiment of the invention there illustrated, l have shown the same applied to a steam boiler 5 adapted for steam heating purposes, but the invention as to many of its features is applicable to .other uses. Herein the burner 7 is located just outside of the combustion chamber, the casing of the latter having an opening through the burner adapted to pro- 'ect an atomized mixture of air and liquid ydrocarbon.

The burner may be of any suitable type, but herein it is shown as provided with an interior oil supply tube 9 communicating at its rear end with an oil supply conduit 11, its opposite end'being closed except for a number of radial ports 13. The tube 9 is contained within a surrounding air tube 15 communicating with the air supply pipe 17. The oil delivered through the lateral oriice 13 is met at` right angles by the air delivered through the air tube 15 and is carried thereby into a mxin chamber 19. There the two are commingle and pass through perforations 21 into a second mixing chamber 23, whence the air and oil thoroughly commingled are delivered through the orifice 25 'of the burner nozzle into the fire or combustion chamber of the heater. The constantly burning pilot light 27 fed from a gas supply is located in front of the burner so as to ignite the fuel as soon as the supply valve-is opened. 1n a burner ot this type it is desirable to maintain a substantially constant relation through the vent pipe 37. To best cooperate with the control device herein provided, oil 1s conveyed by the pump 35 through the pipe 39 to a supply chamber elevated above the burner, where asupply of oil is maintained at a substantially constant `level and from which the burner is supplied through the oil supply pipe 11.

The supply chamber is herein shown as embodied inthe T connection 411 .which is connected laterally `with the oil feed pipe 39 and at its bottom with the oil supply pipe 11. At the top ot the T there is attached by means ,of the nipple i3 the Y connection 45, the remaining branch of the Y being connected to the .overflow pipe 4.7, the latter extending laterally and downwardly and connected to the to of the reservoir 29 to discharge the over ow from the elevated chamber back into the said reservoir. -The top of the Y is preferably closed by the plug 49 so that the chamber therein is closed to the atmosphere except 'through the overflow pipe, reservoir. and vent` pipe 37.

rlhe pump 35 which is driven from the electric motor 51 is designed to deliver oil to the elevated supply chamber in ericess of the maximum requirements of the burner, so that the chamber is kept lled to a oint determined by the location of the over ow pipe. The overflow pipe is preferably givenn a capaclty in excess of that'required for the maximum overflow so as to prevent any tendency ofthe oil pressure'to fluctuate due to a siphon action arising from the choking or damming up of the viscous liquid in its passage from the chamber back to the reservoir. To further avoidy any tendency for such chokingv of the oil, the overflow pipe is preferably free from any sharp turns and is so arranged that a vented communication is maintained between the chamber within the Y 45 and the atmosphere through the overow pipe, reservoir and vent pipe. By this means, not only is there a substantially lll() constant level of oil maintained at all times in the elevated chamber, but a substantially unvarying pressure is maintained on the oil in the supply pipe.

Between the elevated su ply chamber and the burner there is provi ed in the oil line a valve 53 through which the supply of oil to the burner may be varied if required.

The electric motor 51 is employed not only to drive the oil pum 35, but also a pressure creating device, suci asthe air pum 55, which feeds air to the burner throng the air pipe 17, the latter having adjacent the blower the air gauge 57 and means, such as the vrelief valve 59, whereby the air pressure may be regulated.

In order to prevent the su ply of oil to the burner except when air un er-the required pressure is supplied through the air supply pipe 17 but to permit such oil supply when the air pressure is adequate, there is provided in the oil supplypipe 11 an oil cutoli` valve, the lever for which is shown at 61, so arranged that it closes whenever the pressure in the air supply pipe drops below a predetermined amount but opens when the air pressure rises to the required point. For this purpose the valve lever 61 is connected by t e chain 63 tothe end of an arm 65 (see Fig. '2 the latter pivoted at67. The arm rests t rough a knife edged connection 69 on vthe end of a vertically movable rod 71. The lower end of the latter is connected to a plate 73, the'unden side of which is exposed to air pressure fromthe pipe 17 through the connection 75 but is normally depressed by the corrugated or bellows-like metallic connection 77. The end of the valve lever 61 is weighted to normally close the valve, and one end of the lever arm 65 has the weight 79, the weight being so adjusted that when the air pressure in the pi e 17 reaches the required point the plate lifrts against the resiliency of the corrugated connection 77, swinging the lever arm '65 about its pivot 67 to the dotted line position shown, arresting the valve arm 61 and thereby opening the oil supply valve. The latter remains open so long as the necessary Aair ressure is maintained, but as soon as the atter ceases or drops below the required amount the elastic connection 77 forces the plate 73 down,'allowing the Weighted lever 61 to fall and closev the oil valve. The oil supply is therefore romptly shut o ff as soon as the air supply fa s from any cause and any tendency of the oil iiow to persist is stopped.

This prevents the oil from reaching the burner before suliicient air pressure has been built up to properly atomize the oil and also prevents the oil frombacking up through the air supply pipe. At the same time it permits the oil to be fed under the desired pressure established by the elevated supply chamber the moment that the air pressure has reached its required point.

The described devices may be employed in conjunction with the usual devices for automatically starting and stopping the motor 51 under the control of thermostat apparatus, the latter responsive to the pressure of the space to be heated and to the pressure of steam in the heater and to the presence or absence of the flame at the pilot li ht, but, as these devices are well known, t ey are not herein illustrated.

While I have herein shown for the purposes of illustration one specific embodiment of the invention, it is to be understood that the same is submitted for the purposes of illustration and that the details of construction and relative arrangement of parts, as well as the application of the invention, may be varied within wide limits without departing from 'the spirit thereof.

Claims:

1. In a liquid fuelburning apparatus, the combination with a burner, of a fuel supply conduit, a supply chamber elevated above the burner, a vented reservoir, means for supplying fuel to the chamber from the reservoir in excess of the requirements of the burner, said chamber having an overflow conduit extending laterally and dovvnward ly at an inclination to the vertical from said chamber to said reservoir, the overflow con duit having a capacity in excess of that required for the maximum overflow, and providing an air vent passage from the reservoir to the chamber.

2. In a liquid fuel burning apparatus, the combination with a burner, of a fuel supply conduit, a Y-connection providing a supply chamber elevated above` the burner, a vented reservoir, a pump for supplying fuel to the chamber from the reservoir in excess of the requirements of the burner, an overflow pipe connected to one branch of the Y extending laterally and downwardly to the reservoir, said pipe having a capacity in excess of the pump, thereby to maintain a substantially constant level in the chamber and a substantially unvarying pressure on the oil in the supply conduit under all conditions of burner operation, said pipe line providing an air vent for said chamber.

In testimony whereof, I have signed my name to this specification.

ARTHUR H. BALLARD.

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